Objectives. To explore the barriers and facilitators of micronutrient powder (MNP) supplementation to mothers of children aged 6 to 35 months living in the Peruvian cities of Tacna, Loreto, Puno, and Lima. Materials and methods. This qualitative exploratory study with a grounded theory approach was conducted in the Peruvian cities of Lima, Tacna, Loreto, and Puno in 2014. In-depth interviews were conducted with mothers of children younger than 3 years, and observations in health care facilities (HCFs) were made to determine the barriers and facilitators of MNP supplementation. Results. The barriers identified at the health care level were limited access to HCFs, negative rumors regarding the MNP in the clinics, and poor care by health personnel. The barrier at the product (MNP) level was the lack of knowledge about the supplement, including taste and side effects. The barrier at the maternal level was lack of time, neglect, difficulties in preparing the MNP, and opposition to the use of the MNP by the husband. The main facilitators were receiving information from health personnel regarding child improvement, mother’s perception of child’s improvement, and positive testimonies about the effectiveness of the MNP from relatives and neighbors. Conclusions. Barriers regarding MNP use at the health care system level and those associated with the behavior mothers and family/community, which prevent children from consuming the MNP supplement daily, need to be addressed through the development of strategies. Strategies must be developed to overcome the barriers related to the health care system, the MNP, and the behavior of children, mothers, and family/community because these barriers prevent children from consuming the MNP daily.